Manual input devices used for navigation and control of a computing system have a significant impact on the capabilities of the system and the user's overall experience. There are several kinds of manual input devices used for navigation and control of a personal computer, the most common of these including single-pointer, indirect interaction devices, such as a mouse or touchpad, and direct interaction devices, such as a touchscreen and pen and tablet devices.
Most input devices have buttons in addition to their position information. For example, dual-state mechanical buttons are common on mice. Pen digitizers also typically have pressure-responsive devices in the tip and/or stylus barrel, which transmit tip and barrel pressure values, respectively. Most software drivers for pen digitizers implement a form of mouse emulation in process tip-related data. Also, buttons and other mechanisms generally are processed as independent inputs of the input device.